#include <iostream>
#include <vector>
#include <string>

class foo
{
public:
  struct bar {
    int x;
  };

  inline static int a = 0;
  inline static bar b{}; 

  foo(/* args */) = default;
  ~foo() = default;
};





int main() {
   std::cout << foo::a << " " << (foo::b).x;
}